Tripot universal joints are typically employed in automotive axial driveshafts and especially in front-wheel-drive vehicles between the transaxial differential and the driving wheel. The telescopic constant velocity joint such as the tripot should not only transmit the torque at various speeds, angles and telescopic positions but also prevent any vibrations of the engine from being transmitted through the joint and driveshaft to the driving wheel and the vehicle structure. In addition, when the universal joint operates at an angle it should not produce any oscillating axial excitation which may be capable of initiating vibrations in the driveshaft or in the structure of the vehicle.
U.S. Pat. No. 5,203,741 discloses a constant velocity ratio universal joint of the tripod type, comprising an outer joint member with three guide grooves, and an inner joint member with arms each carrying a roller which is able to rotate about, move lengthwise of, and tilt relative to the arm, wherein both the external surface of the roller and each side portion of a guide groove engaged thereby is of a gothic arch cross sectional shape to provide for angular contact between roller and guide groove and improve the guidance of the roller so that it remains aligned in the groove for rolling therealong and with the gothic arch section of the roller and/or guide groove side comprising arcuate portions with different centers of curvature, or having part-elliptical or part-involute portions. The external surface of the roller is a surface of revolution described by rotating, about a central axis of the roller, a line in the shape of a truncated gothic arch, with a flat surface facing the guide groove. As a result, the roller and guide groove side portion engage one another at two spaced points.